GJ 393 is a cool M-dwarf (about 0.43 solar masses, 3,579 K, 0.43 solar radii), 7.0 light-years from Earth. GJ 393 b is a 1.7-Earth-mass planet, with an orbital period of 7.0 days, at 0.054 AU from its star, and an equilibrium temperature near 485 K, discovered in 2021 via radial velocity. The planet betrayed itself through the star's reflex motion — a technique that first revealed worlds around Sun-like stars in the 1990s and remains a workhorse of exoplanet discovery. GJ 393 b orbits well inside Earth's distance from the Sun.